package crazy.collection;

import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;

class SimpleEntry<K, V> implements Map.Entry<K, V>, java.io.Serializable//直接把Map.Entry结构拿过来用
{
	private final K key;
	private V value;
	
	public SimpleEntry(K key, V value)
	{
		this.key = key;
		this.value = value;
	}
	
	public SimpleEntry(Map.Entry<? extends K, ? extends V> entry)
	{
		this.key = entry.getKey();
		this.value = entry.getValue();
	}
	
	@Override
	public K getKey()
	{
		return key;
	}

	@Override
	public V getValue()
	{
		return value;
	}

	@Override
	public V setValue(V value)
	{
		V oldValue = this.value;
		this.value = value;
		return oldValue;
	}
	
	public boolean equals(Object o)
	{
		if (o == this)
		{
			return true;
		}
		if(o.getClass() == SimpleEntry.class)
		{
			SimpleEntry se = (SimpleEntry) o;
			return se.getKey().equals(getKey());
		}
		return false;
	}
	
	public int hashCode()
	{
		return key == null? 0 : key.hashCode();
	}
	
	public String toString()
	{
		return key +"="+value;
	}
	
}


public class Set2Map<K, V> extends HashSet<SimpleEntry<K, V>>//直接把HashSet结构拿来用
{
	public void clear()
	{
		super.clear();
	}
	
	public boolean containsKey(Object key)
	{
		return super.contains(new SimpleEntry<K, V>((K) key, null));
		
	}
	
	public boolean containsValue(Object value)
	{
		for (SimpleEntry<K, V> se : this)
		{
			if (se.getValue().equals(value))
			{
				return true;
			}
		}
		return false;
	}
	
	public V get(Object key)
	{
		for (SimpleEntry<K, V> se : this)
		{
			if (se.getKey().equals(key))
			{
				return se.getValue();
			}
		}
		return null;
	}
	
	public V put(K key, V value)
	{
		super.add(new SimpleEntry<K, V>(key, value));
		return value;
	}
	
	public void putAll(Map<? extends K, ? extends V> m)
	{
		for (K key : m.keySet())
		{
			super.add(new SimpleEntry<K, V>(key, m.get(key)));
		}
	}
	
	public V removeEntry(Object key)
	{
		for (Iterator<SimpleEntry<K, V>> it = this.iterator(); it.hasNext(); )
		{
			SimpleEntry<K, V> en = (SimpleEntry<K, V>) it.next();
			if (en.getKey().equals(key))
			{
				V v = en.getValue();
				it.remove();
				return v;
			}
		}
		return null;
	}
	
	public int size()
	{
		return super.size();
	}
}


